钉形水泥搅拌桩复合地基一维固结解析解  

ONE DIMENSIONAL ANALYTICAL SOLUTION FOR CONSOLIDATION OF A COMPOSITE GROUND WITH T-SHAPED DEEP CEMENT MIXING COLUMNS

作　　者：杨涛[1] 盛志成 王恒栋 YANG Tao;SHENG Zhicheng;WANG Hengdong(School of Environmental and Architecture,University of Shanghai for Science and Technology,Shanghai 200093,China;Shanghai Municipal Engineering Design Institute(Group)Co.,Ltd.,Shanghai 200092,China)

机构地区：[1]上海理工大学环境与建筑学院,上海200093 [2]上海市政工程设计研究总院(集团)有限公司,上海200092

出　　处：《工业建筑》2020年第3期102-108,共7页Industrial Construction

基　　金：国家重点研究发展计划项目(2016YFC0802405)。

摘　　要：钉形搅拌桩是具有扩大头的新型水泥土桩。基于等竖向应变假设,推导出瞬时荷载下端承钉形搅拌桩复合地基桩间土的固结方程,基于双层地基一维固结理论建立了相应的固结解析解。然后,将复合地基固结度解析解与有限元数值解进行比较,评价解析解的计算精度。最后,通过对各主要影响因素的分析,研究钉形水泥搅拌桩复合地基的固结特性。结果表明:钉形水泥搅拌桩复合地基的固结速率随桩的压缩模量、扩大头下部水泥桩的置换率和它周围土体压缩模量的增加而增大。增加扩大头的直径,复合地基的固结速率随之小幅减小。扩大头的长度不到桩长的一半时扩大头长度的变化对钉形水泥搅拌桩复合地基固结速率的影响较小,扩大头的长度超过桩长一半以后钉形水泥搅拌桩复合地基的固结速率随扩大头长度的增加而快速增大。T-shaped deep cement mixing (DCM) column is a new type of DCM column with an enlarged column cap.Based on the equal vertical strain assumption,the equations governing consolidation of the surrounding soil around a fully penetrated T-shaped DCM column was derived under instantaneous load. The corresponding analytical solutions were developed by using the one dimensional consolidation theory of a double-layer ground. Then,the accuracy of the proposed analytical solution was evaluated through the comparison of the consolidation rates of the composite ground from the proposed analytical solution with the FEA. Finally,the main influence factors were analyzed to investigate the consolidation behavior of the composite ground. The results showed that the consolidation rate of the composite ground increased with an increase in the constrained modulus of T-shaped DCM column,the area replacement ratio of the DCM column with small diameter under the enlarged cap and the constrained modulus of the subsoil around it. It decreased slightly with the increase of the diameter of the column cap. The length of the column cap had little influence on the consolidation rate when it was less than half of the length of a T-shaped DCM column. However,it increased rapidly with the increase of the column cap length when the column cap length is larger than half of that of a T-shaped DCM column.

关 键 词：钉形水泥搅拌桩 复合地基 固结 解析解 扩大头 

分 类 号：TU473.1[建筑科学—结构工程]